<template>
    <view class="uni-pagination">
        <view class="uni-pagination__total is-phone-hide">
            共 {{total}} 条
        </view>
        <view class="uni-pagination__btn" :class="currentIndex === 1 ? 'uni-pagination--disabled' : 'uni-pagination--enabled'"
            :hover-class="currentIndex === 1 ? '' : 'uni-pagination--hover'" :hover-start-time="20" :hover-stay-time="70"
            @click="clickLeft">
            <template v-if="showIcon===true || showIcon === 'true'">
                <uni-icons color="#666" size="16" type="arrowleft" />
            </template>
            <template v-else><text class="uni-pagination__child-btn">{{ prevText }}</text></template>
        </view>
        <view class="uni-pagination__num uni-pagination__num-flex-none">
            <view class="uni-pagination__num-current">
                <text class="uni-pagination__num-current-text is-pc-hide" style="color:#409EFF">{{ currentIndex }}</text><text
                    class="uni-pagination__num-current-text is-pc-hide">/{{ maxPage || 0 }}</text>

                <view v-for="(item,index) in paper" :key="index" :class="{'page--active':item === currentIndex}" class="uni-pagination__num-tag tag--active is-phone-hide"
                    @click.top="selectPage(item,index)">
                    <text> {{item}}</text>
                </view>
            </view>
        </view>
        <view class="uni-pagination__btn" :class="currentIndex >= maxPage ? 'uni-pagination--disabled' : 'uni-pagination--enabled'"
            :hover-class="currentIndex === maxPage ? '' : 'uni-pagination--hover'" :hover-start-time="20"
            :hover-stay-time="70" @click="clickRight">
            <template v-if="showIcon===true || showIcon === 'true'">
                <uni-icons color="#666" size="16" type="arrowright" />
            </template>
            <template v-else><text class="uni-pagination__child-btn">{{ nextText }}</text></template>
        </view>
    </view>
</template>

<script>
    import uniIcons from '@/uni_modules/uni-icons/components/uni-icons/uni-icons.vue'

    /**
     * Pagination 分页器
     * @description 分页器组件，用于展示页码、请求数据等
     * @tutorial https://ext.dcloud.net.cn/plugin?id=32
     * @property {String} prevText 左侧按钮文字
     * @property {String} nextText 右侧按钮文字
     * @property {Number} current 当前页
     * @property {Number} total 数据总量
     * @property {Number} pageSize 每页数据量
     * @property {Number} showIcon = [true|false] 是否以 icon 形式展示按钮
     * @event {Function} change 点击页码按钮时触发 ,e={type,current} current为当前页，type值为：next/prev，表示点击的是上一页还是下一个
     */

    export default {
        name: 'UniPagination',
        components: {
            uniIcons
        },
        props: {
            value: {
                type: [Number, String],
                default: 1
            },
            prevText: {
                type: String,
                default: '上一页'
            },
            nextText: {
                type: String,
                default: '下一页'
            },
            current: {
                type: [Number, String],
                default: 1
            },
            total: { // 数据总量
                type: [Number, String],
                default: 0
            },
            pageSize: { // 每页数据量
                type: [Number, String],
                default: 10
            },
            showIcon: { // 是否以 icon 形式展示按钮
                type: [Boolean, String],
                default: false
            },
            pagerCount: {
                type: Number,
                default: 7
            }
        },
        data() {
            return {
                currentIndex: 1,
                paperData: []
            }
        },
        computed: {
            maxPage() {
                let maxPage = 1
                let total = Number(this.total)
                let pageSize = Number(this.pageSize)
                if (total && pageSize) {
                    maxPage = Math.ceil(total / pageSize)
                }
                return maxPage
            },
            paper() {
                const num = this.currentIndex
                // TODO 最大页数
                const pagerCount = this.pagerCount
                // const total = 181
                const total = this.total
                const pageSize = this.pageSize
                let totalArr = []
                let showPagerArr = []
                let pagerNum = Math.ceil(total / pageSize)
                for (let i = 0; i < pagerNum; i++) {
                    totalArr.push(i + 1)
                }
                showPagerArr.push(1)
                const totalNum = totalArr[totalArr.length - (pagerCount + 1) / 2]
                totalArr.forEach((item, index) => {
                    if ((pagerCount + 1) / 2 >= num) {
                        if (item < pagerCount + 1 && item > 1) {
                            showPagerArr.push(item)
                        }
                    } else if (num + 2 <= totalNum) {
                        if (item > (num - (pagerCount + 1) / 2) && item < (num + (pagerCount + 1) / 2)) {
                            showPagerArr.push(item)
                        }

                    } else {
                        if ((item > num - (pagerCount + 1) / 2 || pagerNum - pagerCount < item) && item <
                            totalArr[totalArr.length - 1]) {
                            showPagerArr.push(item)
                        }

                    }

                })
                if (pagerNum > pagerCount) {
                    if ((pagerCount + 1) / 2 >= num) {
                        showPagerArr[showPagerArr.length - 1] = '...'
                    } else if (num + 2 <= totalNum) {
                        showPagerArr[1] = '...'
                        showPagerArr[showPagerArr.length - 1] = '...'
                    } else {
                        showPagerArr[1] = '...'
                    }
                    showPagerArr.push(totalArr[totalArr.length - 1])
                } else {

                    if ((pagerCount + 1) / 2 >= num) {} else if (num + 2 <= totalNum) {} else {
                        showPagerArr.shift()
                        showPagerArr.push(totalArr[totalArr.length - 1])
                    }

                }

                return showPagerArr
            }
        },
        watch: {
            current(val) {
                this.currentIndex = val
            },
            value(val) {
                if (val < 1) {
                    this.currentIndex = 1
                } else {
                    this.currentIndex = val
                }
            }
        },
        created() {
            this.currentIndex = +this.value
        },
        methods: {
            // 选择标签
            selectPage(e, index) {
                if (parseInt(e)) {
                    this.currentIndex = e
                    this.change('current')
                } else {
                    let pagerNum = Math.ceil(this.total / this.pageSize)
                    // let pagerNum = Math.ceil(181 / this.pageSize)
                    // 上一页
                    if (index <= 1) {
                        if (this.currentIndex - 5 > 1) {
                            this.currentIndex -= 5
                        } else {
                            this.currentIndex = 1
                        }
                        return
                    }
                    // 下一页
                    if (index >= 6) {
                        if (this.currentIndex + 5 > pagerNum) {
                            this.currentIndex = pagerNum
                        } else {
                            this.currentIndex += 5
                        }
                        return
                    }

                }
            },
            clickLeft() {
                if (Number(this.currentIndex) === 1) {
                    return
                }
                this.currentIndex -= 1
                this.change('prev')
            },
            clickRight() {
                if (Number(this.currentIndex) >= this.maxPage) {
                    return
                }
                this.currentIndex += 1
                this.change('next')
            },
            change(e) {
                this.$emit('input', this.currentIndex)
                this.$emit('change', {
                    type: e,
                    current: this.currentIndex
                })
            }
        }
    }
</script>

<style lang="scss" scoped>
    .uni-pagination {
        /* #ifndef APP-NVUE */
        display: flex;
        /* #endif */
        position: relative;
        overflow: hidden;
        flex-direction: row;
        justify-content: center;
        align-items: center;
    }

    .uni-pagination__total {
        font-size: 14px;
        color: #999;
        margin-right: 15px;
    }

    .uni-pagination__btn {
        /* #ifndef APP-NVUE */
        display: flex;
        cursor: pointer;
        /* #endif */
				padding: 0 8px;
        line-height: 30px;
        font-size: $uni-font-size-base;
        position: relative;
        background-color: #F4F4F5;
        flex-direction: row;
        justify-content: center;
        align-items: center;
        text-align: center;
        // border-width: 1px;
        // border-style: solid;
        // border-color: $uni-border-color;
    }

    .uni-pagination__child-btn {
        /* #ifndef APP-NVUE */
        display: flex;
        /* #endif */
        font-size: $uni-font-size-base;
        position: relative;
        flex-direction: row;
        justify-content: center;
        align-items: center;
        text-align: center;
    }

    .uni-pagination__num {
        /* #ifndef APP-NVUE */
        display: flex;
        /* #endif */
        flex: 1;
        flex-direction: row;
        justify-content: center;
        align-items: center;
        height: 30px;
        line-height: 30px;
        font-size: $uni-font-size-base;
        color: $uni-text-color;
        margin: 0 5px;
    }

    .uni-pagination__num-tag {
        cursor: pointer;
        margin: 0 5px;
        height: 30px;
        min-width: 30px;
        text-align: center;
        line-height: 30px;
        // border: 1px red solid;
        color: #666;
        // border-width: 1px;
        // border-style: solid;
        // border-color: $uni-border-color;
    }

    .uni-pagination__num-current {
        /* #ifndef APP-NVUE */
        display: flex;
        /* #endif */
        flex-direction: row;
    }

    .uni-pagination__num-current-text {
        font-size: 15px;
    }

    .uni-pagination--enabled {
        color: #333333;
        opacity: 1;
    }

    .uni-pagination--disabled {
        opacity: 0.5;
		/* #ifdef H5 */
		cursor: default;
		/* #endif */
    }

    .uni-pagination--hover {
        color: rgba(0, 0, 0, .6);
        background-color: $uni-bg-color-hover;
    }

    .tag--active:hover {
        color: $uni-color-primary;
    }

    .page--active {
        color: #fff;
        background-color: $uni-color-primary
    }

    .page--active:hover {
        color: #fff;
    }

	.is-pc-hide {
		display: block;
	}

	.is-phone-hide {
		display: none;
	}

	/* #ifdef H5 */
	@media screen and (min-width: 450px) {
		.is-pc-hide {
			display: none;
		}

		.is-phone-hide {
			display: block;
		}

		.uni-pagination__num-flex-none {
			flex: none;
		}

	}
	/* #endif */
</style>
